After 12 dives six miles south of Pearl Harbor, University of Hawaii and Army researchers using deep-diving submersibles and remote underwater drones still have not located the main site of chemical munitions believed to have been dumped there during and after World War II.

They have found “;numerous munitions of varying types, mostly conventional,”; said J.C. King, assistant for munitions and chemical matters in the office of the deputy assistant secretary of the Army for environment, safety and occupational health, in an e-mail yesterday.

He said of munitions recorded by high-definition video cameras are “;multipurpose (conventional or chemical).”;

The Army has contracted the Hawaii Undersea Research Laboratory submersibles Pisces IV and V to explore the ocean bottom in an area dubbed “;Hawaii-05”; by the Army. The 2 1/2 -week project will end March 19.

Seventeen dives by the submersible and an additional six by remotely operated vehicles are planned.

The purpose of the $3 million Army project is to determine the risks of some 600 tons of chemical weapons dumped there. The Army plans to test water and sediment samples taken from the muddy bottom.

King said, “;The goal is to assess the impact of the munitions on the ocean environment and the impact of the ocean environment on munitions.”;

The Pearl Harbor site is one of three off Oahu where the Army dumped 2,558 tons of chemical agents, including blister agents lewisite and mustard gas and blood agents cyanogen chloride and hydrogen cyanide. The practice of ocean dumping was banned in 1972.

The largest dump is reported to be in area 10 miles west of the Waianae Coast.

The Army has said it believes 16,000 M47-A2 bombs containing 598 tons of mustard gas were dumped at “;Hawaii-05”; around Oct. 1, 1944. Each chemical bomb weighs 100 pounds and is nearly 32 inches long.

Most of the dives are at about 1,500 feet.

King has been a passenger on at least two of the dives.

“;As expected,”; King said, “;the munitions are meters apart and generally of the same type (e.g., a series of .50-caliber boxes, a series of projectiles). This is expected because ship loads would have been from storage, and we generally store and transport these same munition types together.”;